If you're really that bothered with the framing thing, here's from a DVD website:
It only took five years to finally surface, and now it looks like the Back to the Future set is a bum steer. Universal Studios is issuing a (quiet) recall of the just-released collection because of the widescreen misframing of parts II and III (I is unaffected). If you bought the set and want corrected copies, send in your two discs without the case and a letter with the following information: Name, Full Mailing Address, Daytime Phone Number, Reason for Return and Return Address. Send all of this to:
Back to the Future DVD Returns
PO Box 224468
Dallas, Texas 75260
Universal will exchange Back to the Future parts II and III for copies with the updated framing in late February 2003. You can send the DVDs back now or wait until then.
You ask, is it worth all the trouble? Or are you just gonna stick with the copy that you have?